let isDone: boolean = true
let list = [1,2,3]
let tsList: number[] = [1,2,3]
let tsList2: Array<number> = [1,2]
let x: [number, string] = [1, 'a']
enum Color {Red, Green, Blue}
let c: Color = Color.Green;
console.log(c)

enum Month { Jan=31, Feb=28, Mar=31 }
const mar:Month = Month.Mar
console.log(mar)

interface LabelledValue {
    label?: string,
    size?: number
  }
  
  function printLabel(labelledObj: LabelledValue) {
    console.log(labelledObj.label);
  }
  
  let myObj = {size: 10};
  printLabel(myObj);

  function DateTransfer(timeStamp:number) {
      console.log(new Date(timeStamp))
  }
  DateTransfer(1608598706846)

//   表达式声明函数
  let myFunc = function() {

  }

  interface StringArray {
    [index: number]: string;
  }
  
  let myArray: StringArray;
  myArray = ["Bob", "Fred"];
  
  let myStr: string = myArray[0];

